Apparatus for applying adhesive



Sept. 20, 1966 H. w. BOOTHROYD ETAL 3, 3,

APPARATUS FOR APPLYING ADHESIVE Filed July 23, 1963 70 fill/anion? Harold h/Boothrqyd Harry Phillips B fhez'rAttorney United States Patent APPARATUS FGR APPLYING ADHEHVE Harold W. Bootlrroyd, Wenham, and Harry Phiilips,

Hamilton, Mass assignors to United Shoe Maehinery tCorporation, Fliernington, N.J., a corporation of New Jersey Filed July 23, 1963, Ser. No. 297,073 6 Claims. (Cl. 118-202) This invention relates to apparatus for applying adhesive and is especially concerned with an improvement in adhesive applying apparatus of the type in which the adhesive is applied to work pieces by means of a rotary member such as a roll or wheel. In apparatus of this type, the adhesive applying wheel is usually carried on a shaft that is journaled in a casing shaped to receive the major portion of the wheel and to provide adjacent to a part of its peripheral surface a supply chamber to which the adhesive is supplied from some outside source. Frequently, adhesive applying apparatus of this general type is used to apply molten thermoplastic adhesive which may be supplied to the supply chamber as, for example, by feeding the leading end of a solid rod of adhesive into the inlet end of a passageway formed in the casing which is heated to melt the solid rod so that molten adhesive is delivered to the supply chamber from the discharge end of the passageway. The supply chamber is usually closed in part by a metering bar placed where the rotating applying wheel leaves the casing and, due to the viscosity of the molten adhesive, the pressure of the molten adhesive tends to build up in the supply chamber, adjacent to the metering bar to a value considerably higher than that of the atmosphere to which pressure the molten adhesive is exposed, adjacent to a stringer roll, or similar element, where the rotating applying wheel reenters the casing.

During the operation of adhesive applying apparatus of the aforementioned type, there is a tendency for the molten adhesive to enter the bearings in which the applying wheel shaft and/or stringer roll shaft, are journaled by gradually working along through the space between the side of the wheel and the casing. In time the action of heat causes the molten adhesive to break down, at least partially, and carbonize thus greatly increasing the friction between the wheel shaft and bearing and eventually, if not corrected by cleaning out the charred adhesive, resulting in bearing failure. It is a principal object of this invention to overcome this serious diificulty in a very effective yet relatively simple and inexpensive manner by causing a continuous flow of the molten adhesive through the shaft bearing and utilizing the molten adhesive itself as a lubricant.

To this end and in accordance with a feature of this invention, in the herein illustrated apparatus which, in common with adhesive applying apparatus of the type here under consideration, has a casing formed to receive an applying wheel and to provide a supply chamber adjacent to a metering bar, means are provided for causing a continuous flow of molten adhesive from a point in the supply chamber where pressure of the adhesive is relatively high, through the shaft bearings to be lubricated and thence to a point in the casing where the pressure is low. More particularly, the casing which is preferably heated to melt adhesive being introduced into the supply chamber is formed with a first passageway opening at one end into the supply chamber in the vicinity of the metering bar where pressure of the molten adhesive is relatively high and at its other end into a lubricating groove, or equivalent passage, associated with the bearing to be lubricated and with a second passageway connecting this lubricating groove to a portion of the wheel receiving recess in the casing where the pressure of adhesive 3,273,531 Patented Sept. 20, 1966 is relatively low, thereby causing a continuous flow of molten adhesive through the bearing to lubricate the same. In addition, this continuous flow of adhesive greatly reduces and practically eliminates any tendency for the adhesive to carbonize or break down Within the bearing and at the same time flushes out any particles of dirt or other foreign matter from the bearing.

The above and other objects and features of the invention will appear in the following detailed description of a preferred embodiment illustrated in the accompanying drawings and will be pointed out in the claims.

In the drawings:

FIG. 1 is a view in side elevation of an adhesive applying apparatus embodying features of this invention with certain parts shown in vertical section substantially on line II of FIG. 2 and looking in the direction of the arrows;

FIG. 2 is a plan view of the apparatus illustrated in FIG. 1 with parts shown in horizontal section for the most part substantially on line IIII of FIG. 3 but with a small portion thereof substantially on line IIa-IIa of FIG. 1, looking in the direction of the arrows in each case; and

FIG. 3 is a view in side elevation of the apparatus with certain parts in vertical section substantially on line III- III of FIG. 2 and looking in the direction of the arrows.

Referring to these drawings, the adhesive applying apparatus therein disclosed includes a casing, indicated generally by the reference character 10, and comprising a body portion 12, a rear cover 14 and a front body portion 16 which are held together in assembled relation by means of suitable bolts or screws, not shown. The body portion 12 is cut away along a surface indicated by the reference character 2t and of the shape shown in FIG. 1 thus to provide a recess for receiving an applicator wheel 22 carried by a shaft 24 and'also for receiving a so-called stringer roll 26 carried by a shaft 28. The surface 20 in addition includes portions on which there are mounted a metering bar 30 adjustably secured in place by means of a screw 32, a scraper blade 34 held in place by a screw 36 and a socalled zone 'bar 38. As will be apparent from an inspection of FIG. 1, the zone bar 38 in effect separates the recess in the body portion 12 which surrounds the wheel 22 into a supply chamber 40, adjacent to the metering bar 30 where the rotating wheel 22 leaves the recess, and a return chamber 42 in the vicinity of the stringer roll where the wheel re-enters the recess.

The wheel shaft 24 passes through a seal arrangement including packing rings 50, '50 and a gland 52 held in place by means of screws 54, 54, and is journaled on one side of the applying wheel in a bearing bushing 56 and on the opposite side of the wheel in a bearing block 58 carried by the rear cover 14, FIG. 2. The shaft 24 is driven from an outside power source not shown, so as to rotate the applying wheel 22 in the direction of the arrow, FIG. 1, and the shaft 28 is driven from this same source through gearing not shown, in the opposite direction as is also indicated by an arrow in FIG. 1.

The front portion 16 of the casing is provided with a passageway leading from the outside of the casing to the supply chamber 40 comprising a straight bore 60 which is in communication at one end with the bore 62 of an inlet bushing 64 and at its other end, through a short cross passage 66 with a spiral passageway, formed by a spiral groove 68 of decreasing depth and one side face of the wheel 22, which passageway extends beyond the peripheral surface of the wheel and thus opens into the supply chamber 40. When molten adhesive is fed through the spiral passageway into the supply chamber 40, for example by feeding the leading end of a solid rod of adhesive into the bore 60 in the front body portion 16 of the casing, where the rod is heated and melted by the effect of electric heating elements one of which appears in FIG. 3 and is identified by reference character 70, the side face of the rotating applying wheel pposite to the spiral groove 68 tends to draw the molten adhesive along through this groove and thus provides somewhat of a pumping action as is explained in more detail in a copending application for United States Letters Patent Ser. No. 267,011 filed Mar. 21, 1963 in the name of Harold W. Boothroyd to which reference may be made also for a disclosure of a mechanism for feeding solid rod in the above manner.

Preferably, the rod feeding mechanism, when in operation, is adapted to supply molten adhesive to the chamber 40 at a rate slightly in excess of the maximum rate at which adhesive is applied to work pieces fed along, in succession, past and in contact with flanges 72, 74 formed on the wheel 22. The latter rate is, of course, determined by the clearance between the two mentioned flanged portions on the applying wheel and the metering bar 30, the middle portion of this bar acting to scrape 011 and remove all adhesive from the peripheral surface of the wheel between the flanges. Therefore, the supply chamber 40 will eventually become filled with adhesive as does an adjoining chamber 80 formed in the body portion 16, FIG. 1. Located within the chamber 80 is a pressure sensitive bellows 82 provided with a piston rod 84 carrying two switch operating abutments 86, 88. These two abutments are adapted to engage the plungers 90, 92 of a microswitch 94 which forms a part of an electrical circuit arranged to control the operation of the rod feed wheels generally in the same manner as is disclosed in United States Letters Patent No. 2,824,541, issued on Feb. 25, 1958 in the name of Hans C. Paulsen. This mechanism forms no part of the present invention and hence need not be further described or discussed.

When the apparatus which has been so far described is in operation, the supply chamber 40 will be kept full of molten adhesive and the pressure of the adhesive in this chamber will build up as a result of the pumping action of the applying wheel 22 on adhesive delivered into the chamber 40 through the spiral passageway 68 and also because of the action of the peri heral surface of the wheel in drawing molten adhesive returned to the chamber 42 through the space between the wheel and the zone bar 38, this clearance being somewhat greater than the maximum clearance between the meter bar 30 and the flanges 72, 74 on the applying wheel. As already indicated, when pressure of the adhesive in the supply chamber 40 reaches a predetermined maximum value, the action of the rod feed wheels, or other means for applying molten adhesive, is temporarily stopped and is not resumed until the pressure of the adhesive is reduced, by the application of adhesive to work pieces, to a predetermined minimum value. On the other hand, the pressure of the adhesive in the chamber 42 adjacent to the stringer roll 26, where the wheel re-enters the casing, is much less and in fact is substantially atmospheric. This pressure differential is utilized in the following manner in accordance with this invention.

The bearing bushing 56 is provided with an exterior axial groove 100 which is in communication with an interior axial groove 102 which extends entirely through this bearing bushing, and also with a bore 104 in the casing portion 16, and this last mentioned bore is connected to a short cross passage 106 which opens into the supply which is in communication with a groove 118 formed in Y a side wall of the body portion 16 and extending, FIG. 3, just beyond the periphery of the stringer roll 26 to open into the return chamber 42. As will be apparent, with this arrangement when the apparatus is in operation, due

to the above described pressure differential, there will be a continuous flow of molten adhesive through the wheel shaft bearing provided by the bushing 56 and also through the stringer roll shaft bearing provided by the bushing 114. This flow of molten adhesive will provide a continuous supply of the molten adhesive which it has been found serves as a satisfactory lubricant, to the mentioned bearings and in addition will continually keep these bearings clean and free from any dirt or other extraneous matter which might interfere with their proper operation. Moreover, inasmuch as the molten adhesive is continually circulated through the mentioned passageways from the supply chamber to the return chamber, there is very much less tendency for the molten adhesive to break down or carbonize and charring of the adhesive in the bearings is thus avoided.

Similarly, the bearing block 58 is provided with an axially extending groove 120 which at one end is in communication with a radial groove 122, formed in the cover 14 and extending slightly beyond the periphery of the applying wheel 22 thus to open into the chamber 40. At its other end, the groove 120 opens into a cup shaft recess 124, formed in one side of the applying wheel 22, FIG. 2. Another radial groove 126, formed in the cover 14 is connected at one end to the recess 124 by a short groove 127 in the block 58, and at its other end to the return chamber 42, adjacent to the stringer roll 26, FIG. 1. A small cover plate 128 is secured to the bearing block 58 to seal the groove 122 from the recess 124 in this particular location. With the arrangement just described, when the apparatus is in operation, molten adhesive from the supply chamber 40 flows through the grooves 122, 120, recess 124 and groove 126 to the return chamber 42 so that the bearing formed in the block 58 is continuously supplied with lubricant, i.e. the molten adhesive, and is kept clean and free from dirt or other extraneous matter.

As indicated above, the applying wheel bearing shaft 24 extends outwardly to the casing 10 through a sealing arrangement including a gland 52 and packing rings 50, 50. The stringer roll shaft 28 also extends outwardly of the casing through a somewhat similar sealing arrangement including packing rings 130 and a compression nut 132, FIG. 2. By providing a continuous flow of adhesive through the bore 110, grooves 116 and 118 to the return chamber 42, the pressure of the molten adhesive in the vicinity of these two sealing arrangements is relatively low and danger of leakage is correspondingly reduced.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

1. Apparatus for applying adhesive comprising a casing formed to provide a recess for receiving a rotary applying wheel, am applying wheel mounted on a shaft, a bearing associated with the casing for journaling said shaft with a major portion of the applying wheel in said recess, a member located substantially within the confines of the casing and cooperating with the peripheral surface of the wheel in a location where the wheel leaves the casing for determining the amount of adhesive carried by the wheel, and means for introducing adhesive into said recess at a point adjacent to said member, said casing and bearing being formed to provide passageways leading from a point in the recess adjacent to said member, through the bearing, to a point in the recess adjacent to the location where the wheel re-enters the casing, whereby a continuous flow of adhesive through said bearing, to lubricate and clean the bearing, is provided when the applying wheel is rotated in a direction toward said member.

2. Apparatus for applying adhesive comprising a casing formed to provide a recess for receiving a rotary applying wheel, an applying wheel mounted on a shaft, bearings associated with the casing for journaling said shaft with a major portion of the applying wheel in said recess, a member located substantially within the confines of the casing and Cooperating with the peripheral surface of the wheel in a location where the wheel leaves the casing for determining the amount of adhesive carried by the wheel, means for heating said casing and wheel, and means for introducing molten adhesive into said recess at a point adjacent to said member, said casing and bearings being formed to provide passageways leading from a point in the recess adjacent to said member, through the bearings, to a point in the recess adjacent to the location where the wheel re-enters the casing whereby a continuous flow of molten adhesive through said bearings, to :lubric-ate and clean the bearings, is provided when the applying Wheel is rotated in a direction toward said member.

3. Apparatus for applying adhesive comprising a casing formed to provide a recess for receiving a rotary applying wheel, an applying wheel mounted on a shaft, bearings associated with the casing for journaling said shaft with a major portion of the applying wheel in said recess, a member located substantially within the confines of the casing and cooperating with the peripheral surface of the wheel in a location where the wheel leaves the casing for determining the amount of adhesive carried by the wheel, a stringer roll carried by a stringer roll shaft, bearings associated with the casing for journaling the stringer roll shaft with the stringer roll adjacent to the periphery of the wheel where the wheel re-enters the casing, and means for introducing adhesive into said recess at a point adjacent to said member, said casing and said wheel shaft bearing and stringer roll shaft bearing being formed to provide passageways leading from a point in the recess adjacent to said member, through the wheel shaft and stringer roll shaft bearings, to a point in the recess adjacent to the stringer roll, whereby a continuous flow of adhesive through said wheel shaft and stringer roll shaft bearings, to lubricate and clean the bearings, is provided when the applying wheel is rotated in a direction toward said member.

4. Apparatus for applying adhesive comprising a casing formed to provide a recess for receiving a rotary applying wheel, an applying wheel mounted on a shaft, a bearing associated with the casing for journaling said shaft with a major portion of the applying wheel in said recess, a member located substantially within the confines of the casing and cooperating with the peripheral surface of the wheel in a location where the Wheel leaves the casing for determining the amount of adhesive carried by the wheel, a stringer roll carried by a stringer roll shaft, a bearing associated with the casing for journaling the stringer roll shaft with the stringer roll adjacent to the periphery of the wheel where the wheel reenters the casing, means for heating said casing and wheel, and means for introducing molten adhesive into said recess at a point adjacent to said member, said casing and said wheel shaft bearing and stringer roll shaft bear-ing being formed to provide passageways leading from a point in the recess adjacent to said member, through the wheel shaft and stringer roll shaft bearings, to a point in the recess adjacent to the stringer roll, whereby a continuous flow of molten adhesive through said wheel shaft and stringer roll shaft hearings, to lubricate the bearings, is

provided when the applying wheel is rotated in a. direction toward said member.

5. Apparatus for applying adhesive comprising a casing formed to provide a recess for receiving a rotary applying wheel, an applying wheel mounted on a shaft, a bearing associated with the casing for journaling said shaft with a major portion of the applying wheel in said recess, a member located substantially within the confines of the casing and cooperating with the peripheral surface of the wheel in a location where the wheel leaves the casing for determining the amount of adhesive carried by the wheel, a stringer roll carried by a stringer roll shaft, a bearing associated with the casing for journaling the stringer roll shaft with the stringer roll adjacent to the periphery of the wheel where the Wheel re-enters the casing, and means for introducing adhesive into said recess at a point adjacent to said member said casing and said stringer roll shaft bearing being formed to provide passageways leading from a point in the recess adja cent to said member, through the stringer roll shaft bearing, to a point in the recess adjacent to said stringer roll, whereby a continuous flow of adhesive through said stringer roll shaft bearing, to lubricate and clean the bearing, is provided when the applying Wheel is rotated in a direction toward said member.

6. Apparatus for applying adhesive comprising a casing formed to provide a recess for receiving a rotary applying Wheel, an applying wheel mounted on a shaft, bearings associated with the casing for journaling said shaft with a major portion of the applying wheel in said recess, a member located substantially within the confines of the casing and cooperating with the peripheral surface of the wheel in a location where the wheel receives the casing for determining the amount of adhesive carried by the Wheel, a stringer roll carried by a stringer roll shaft, bearings associated with the casing for journaling the stringer roll shaft with the stringer roll adjacent to the periphery of the wheel where the wheel re-enters the casing, means for heating said casing and wheel, and means for introducing molten adhesive into said recess at a point adjacent to said member, said casing and stringer roll shaft bearings being formed to provide passageways leading from a point in the recess adjacent to said member, through the stringer roll shaft bearings, to a point in the recess adjacent to said stringer roll, whereby a continuous flow of molten adhesive through said stringer roll shaft bearings, to lubricate and clean the bearings, is provided when the applying wheel is rotated in a direction toward said member.

References Cited by the Examiner UNITED STATES PATENTS 12/1916 Bohaker 118-262 4/1957 Kelley 118-202 X 

1. APPARATUS FOR APPLYING ADHESIVE COMPRISING A CASING FORMED TO PROVIDE A RECESS FOR RECEIVING A ROTARY APPLYING WHEEL, AN APPLYING WHEEL MOUNTED ON A SHAFT, A BEARING ASSOCIATED WITH THE CASING FOR JOURNALING SAID SHAFT WITH A MAJOR PORTION OF THE APPLYING WHEEL IN SAID RECESS, A MEMBER LOCATED SUBSTANTIALLY WITHIN THE CONFINES OF THE CASING AND COOPERATING WITH THE PERIPHERAL SURFACE OF THE WHEEL IN A LOCATION WHERE THE WHEEL LEAVES THE CASING FOR DETERMINING THE AMOUNT OF ADHESIVE CARRIED BY THE WHEEL, AND MEANS FOR INTRODUCING ADHESIVE INTO SAID RECESS AT A POINT ADJACENT TO SAID MEMBER, SAID CASING AND BEARING BE- 